Indirect water-heating system.



E. RUUD. I INDIRECT WATER HEATI G SYSTEM.

Patented N0v.15,1 91 0.

2 EHBBTS-BHEBT 1.

APPLICATION FILED MAY 13 1909. I

E. RUUD. I INDIRECT WATER HEATING SYSTEM."

I 5,8 IAPPLIOATIOH rum mm 12, 1909. Pat iented NOV 15,1910.

2 SHEETS-SHEET 2.

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EDWIN RUUD, OF PITTSBURG, PENNSYLVANIA.

INDIRECT WATER-HEATING SYSTEM;

Specification of Letters .Eatent.

Patented Nov. 15, 1910.

Application filed May 12, 1909. Serial No..495,490.

Supply of water. in the circulating coils of,

not practical-in connection with hard water,

and sulfur-and other waters containing impurities, for the reason that" the lime and other solids and impurities thereof deposit in the heatercoils or on its heating surfaces,

- and such accumulations detract greatly from the fiiciency-of. the heater and result finally in destroying the same. To overcome this difiiculty indirect heating is resorted to, z. 0.

heat derivedfrom a substantially unchanging body of water circulating through the heater and through coils or other means exposed to the tank or the water therein, thus heating the latter indirectly by conduction. The invention as here embodied provides a means of communication between the storage tank and the heater circulating system, such means providing an elastic air pocket which forms, in effect, a partition or dia- I phragm between the waters of the tank and circulating system and prevents intermingling excepting when necessary to replenish the supply in the latter. The water of the heater is thus maintained at main pressure, as in thetank, and the operation is so thoroughly automatic as to require absolutely no attention after being once started.

The heater and its coils or circulating sysan indirect water heating storage system" tem may be filled initially with soft \\'ater,-

or the same may be charged with hard water om 1e s ora e 2111i. 11 e1 ier ca. e 01 fr tl t g t l I tl s 1l such addltional amounts of hard water are admitted as are necessary to keep the appawith soft water, hard water for such use is not greatly detrimental, as the few gallons required do not carry suflicient deleterious matter to be of any reat moment, and the same is true of the comparatively small replenishing amounts subsequently admitted.

The invention maybe variously embodied and applied, Figure l offfthe accompanying drawings showing insection one adaptation thereof, and Figs. 2 and 3 illustrate other embodiments. p 1

Referring to the drawings, 2is any suitable circulating water heater, preferably of the Ruud type, with the usual risers or circulating pipes 3 and 4, the water'entering through3 and flowing outward through 4:. These pipes connect, respectively, with the heads or manifolds 5 and 6 atthe end'of storage tank 7 8 is one of a series of duplicate coils or return bends within the tank and connect ings heads 5 andti, with the upper branch inclined slightly to facilitate the circulation. These coils or bends comprise only vone of various circulating heat-conducting means that may be employed, and it will be understood the invention is not limited in this regard.

With the heater-and coils or other circu lating means filled and the heater in operation the water will maintain a continuous circulation, at least until the water in the tank has become fully heated, the inclination of the upper branches of the coils or bends, in the adaptation shown, inducing movement of the water as its heat is absorbed by'the cooler water of the tank, causing the same to flow back to the heater and thus maintain continuous circulation. A

single charge or volume of water is thus There is, however, unavoidable shrinkage of the water in the heater through leakage and 'other causes, and in the absence of replenishing means the heater would eventually run dry and burn out. This the present invention avoids by maintaining the water in the heater at tank pressure, with means for automatically admitting water thereto as may be necessary to keep vthe heater and circulating means constantly filled. In the adaptation of Fig- 1, this is accomplished by two chambers Qand 10, the former super-- posed on the latter with pipe 11 connecting the bottom of chamber 9 with head 5 of outflow riser 4. A pipe 12 connects the bottom circulatin of chamber 10 with tank 7. Chambers 9 and -10 communicate through pipe 13 rising in chamber 9 nearly to the top thereof.- Chamber 9 is necessarily at a greater elevation than the water circulating means of the heater.

The heater may be filled initially either from tank 7, or with soft water through thefilling pipe 14 connected to one of the risers. If from tank 7 valve 15 in pipe 12 is opened and water flows outward through chambers the circulating system, when the pet-cock is closed. But a pocket of air remains in the upper portion of chamber 9, the approximate level of the water in said chamber before being heated being at substantially the plane a-a, Fig. 1, and with water extending to approximately the top of tube 13. When the heater is in operation, the expansion due to the rise in temperaturewill raise the Water level in chamber 9 to approxi 'mately the line ?)'b, the resulting pressure forcing the air downwardly through tube 13 and placin the level in chamber 10 at substantially tie plane 0c.

From the foregoing it will be seen that variations of temperature of the water and the resulting expansion and contraction will causethe air pocketto shift or oscillate, as it were. But at ,all times said air pocket forms a flexible cork, partition or diaphragm between the water of the tank and the water of the circulating system and prevents them from mingling, at the same time maintaining the water of the circulating I system at the pressure of the waterin" the Shrinkage of water in the circulating system, due to leakage or other causes, results of course in lowering the level in chamber 9 and permits a corresponding rise and overflow into said chamber from pipe 13. But obviously the quantity of water thus added to the circulating water cannot be more than the shrinkage 'sufi'ered by the water, and the amount should be so small as to be negligible so far as its deleterious properties are concerned. 1

As before indicated, even if the circulating system is filled in the first place with hard water it is not seriously objectionable so long as the same is not constantly changed, nor are the slight replenishments, above ndicated, objectionable. The main purpose is veil'ective manner.

within the tank substantially separate, and

this the invention accomplishes in a most In the adaptation of Fig. 2, the two chambers 17 and 18 (corresponding to chambers 9 and 10) are separated and connectedby the upwardly arched pipe 19, the"function of which is the'same as pipe '13, Fig. 1.

In the construction shown in Fig. 3, the chamber in which the air is confined which forms the water separating cork partition or diaphragm is embodied in pipe 20, here shown in horizontal osition, with depending leg 21 at one en thereof connected to pipe11 leading to the circulating system, and the other end connected by a like depending'leg 22 to pipe 12 from tank 7. The several parts are so arranged and proportioned that under normal conditions the water levels in legs 21 and 22 are beneath the plane of pipe 20. At least this istrue of leg 22 even though the expansion due to heating the water may force it part" way into pipe 20 from leg 21, the intervenin air space 'or pocketp'revent ing the waters rom mixing. But when shrinkage of the circulating water occurs, its level lowers in'leg 21 and the tank pressure forces the level upward in leg 22 and passes a suflicient quantity through .pipe20to replace that which has been lost. The level of the circulating water being thus restored the dividing air pocket again becomes effective, as will be understood.

It will be understood from the foregoing that the invention maybe variously em bodied and applied, and hence I do not desire to restrict myself to any specific arrangementof apparatus for putting the same into efiect. a

1. The combinationv of a water heater, a storage tank, water circulating means for the heater imparting heat to the tank, and a two-part chamber at the exterior of the tank with the parts thereof communicating with each other and connected respectively to the tank and to the circulating means, the chamber providing a pocket forair confined between and separating the water of the circulating means from the water of the storage tank.

2. The combination of a water heater, a

storage tank, water circulating means for the heater imparting heat to the tank, two

p1pesone extending from the circulatin means and the other from the tank, an

. means at the exterior of-the tank providing ata 3. The combination of a water heater, a

greater elevation than the circulatin g'means andin communication therewith, and a connection extending .upwardly tfromithe tank,

and communicating with the said chamber int higher than 'where-the-latter commumcates with the circulating means.

4. The-combination of a water heater, a

I storage tank, water circulating means for the heater imparting heat to the tank, a chamber located at theext'erior of the tank end of the chamber and the circulating and above the circulating means, means establ shmg communicationbetween the lower means, and'means extending upwardly with its lower end in communication with the tank and its upper end in communication with the said chamber above the lower end of the latter.

5. The combination, of a water heater, a storage tank for the'water under pressure, water. circulating means for the heater imparting heat to the tank, an air-pocket-form- 1ng chamber at the exterior of the tank and at agreater elevation than the circulating means and having communicating parts thereof connected respectively to the latter and to the tank, and a valved air outlet for the circulating means. 6 p v In testimony whereof I afiix my signature "in presence of two witnesses.

EDWIN BUUD. "\Vitnesses J. M. Nesm'r,

A. C. \VAY. 

